The characteristics of permafrost beneath a lake in the Beiluhe basin on the Tibetan Plateau were studied based on the ground temperature monitoring. The result shows that the monitored lake did not penetrate through the permafrost. During 2009 to 2010, the permafrost table beneath the lake varied greatly, while the permafrost table beneath the nearby natural alpine meadows was basically unchanged. Apart from the center of the lake, the volumetric ice contents of permafrost beneath and around the lake increased gradually, and the depth of zero annual amplitude of ground temperature and mean annual ground temperature decreased, respectively. During the observation, ground temperature of shallow permafrost increased yearly, but ground temperature of deep permafrost and beneath natural field still unchanged. Ground temperature of permafrost beneath natural field was obviously lower than that under the lake.

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